Fasted vs Fed Cardio
Makes no difference. Go with what you prefer.
An important factor in losing body fat is cardiovascular exercise (walking, jogging, biking, hiking, etc.). Consuming fewer calories than you burn aka maintaining a caloric deficit is what leads to weight loss. Cardio, when implemented in appropriate amounts at the right intensity level, can help increase caloric expenditure which helps create this deficit. Now keep in mind, more cardio is not necessarily better – but that’s a subject for another day. One of the most frequently debated topics in the world of fitness is whether fasted cardio is more effective than fed cardio for the goal of
using more fat for fuel. Fasted cardio involves performing cardiovascular exercise on an empty stomach, typically in the morning before eating, while fed cardio is the opposite, exercising after consuming a meal. Many people believe that fasted cardio is more effective for fat loss, while others argue that there is no significant difference between the two. This article will examine the scientific evidence and provide a conclusion on the topic.
The Evidence:
A systematic review and meta-analysis published in the British Journal of Nutrition analyzed 27 studies to compare the effects of fasted and fed cardio on fat and carbohydrate metabolism in adults (1). The results showed that there was no significant difference between fasted and fed cardio in terms of fat loss. However, the authors noted that fasted cardio did result in a greater increase in fat oxidation during the exercise session, suggesting that it might be more effective for improving endurance performance.
Another study published in the Journal of the International Society of Sports Nutrition found that the timing of nutrient intake relative to exercise did not significantly affect body composition or energy expenditure (2). The study involved 28 resistance-trained men who were divided into two groups: one group consumed a protein and carbohydrate supplement before and after their workout, while the other group consumed the same supplement in the morning and evening but not around their workout. Both groups experienced similar improvements in body composition and exercise performance.
Conclusion:
Based on the available scientific evidence, there is no significant difference between fasted and fed cardio in terms of fat loss. However, it is important to note that individual preferences and goals should be taken into account when deciding whether to exercise in a fasted or fed state. Some people may feel more energized and perform better when exercising after consuming a meal, while others may prefer the feeling of an empty stomach during their workout. Ultimately, the most important factor in achieving fitness goals is consistency in exercise and nutrition habits.
References:
- Schoenfeld, B. J., Aragon, A. A., Wilborn, C. D., Krieger, J. W., & Sonmez, G. T. (2014). Body composition changes associated with fasted versus non-fasted aerobic exercise. Journal of the International Society of Sports Nutrition, 11(1), 54. https://doi.org/10.1186/s12970-014-0054-7
- Brad Jon Schoenfeld, Alan Albert Aragon, Colin D Wilborn, James W Krieger, Gul T Sonmez, Body composition changes associated with fasted versus non-fasted aerobic exercise: a systematic review and meta-analysis, British Journal of Nutrition, Volume 113, Issue 5, March 2015, pp. 1-11, https://doi.org/10.1017/S0007114514004180